WO1993022538A1

WO1993022538A1 - Method for excavating tunnels, utilisation of a foaming agent and new composition

Info

Publication number: WO1993022538A1
Application number: PCT/FR1993/000394
Authority: WO
Inventors: Nikita Tyrtoff; Michel Barbarin
Original assignee: Seppic, Societe D'exploitation De Produits Pour Les Industries Chimiques
Priority date: 1992-04-30
Filing date: 1993-04-22
Publication date: 1993-11-11
Also published as: GR3021184T3; FR2690709A1; NO944051L; EP0638137B1; DE69304691T2; DE69304691D1; ES2092307T3; NO944051D0; ATE142743T1; FR2690709B1; DK0638137T3; AU4263393A; EP0638137A1

Abstract

The invention relates to a method for the excavation of tunnels by means of a driving shield, particularly a driving shield of the ground pressure type, comprising a cutting disc and a confinement chamber. A foam is injected in front of said cutting disc and/or into said confinement chamber, the foam being generated by activation of a foaming agent comprising at least one surfactant and at least one foaming aid. The invention also relates to the utilisation of said foaming agent for the excavation of tunnels, as well as a new composition comprising an alkylpolyglycoside as surfactant and a foaming aid.

Description

PROCESS FOR EXCAVATING TUNNELS, USE OF A FOAMING AGENT AND NOVEL COMPOSITION

The present invention relates to a method of excavating tunnels by means of a digging shield, in particular a shield of the earth pressure type, comprising a cutting disc and a confinement chamber, as well as the use of an agen foaming agent for tunnel excavation and a new composition useful as a foaming agent.

For the excavation of cylindrical galleries or tunnels in different types of terrain, devices known as digging shields have been used for several decades. This type of device usually comprises a metal cylinder or cutting disc, driven in rotation about its axis, and the diameter of which corresponds to that of the tunnel to be excavated. This cutting disc carries felling tools and / or crushing wheels allowing the excavation of the ground.

In order to stabilize the working face, several solutions have been envisaged, one of the most recent and most advantageous of which is stabilization using the pressure of the excavated earth and confined in a cutting chamber or confinement chamber. , located at the rear of the cutting cylinder. The latter is provided with openings slots allowing the passage of the cuttings towards the containment chamber. The cuttings accumulated in the containment chamber can be removed by means of an extraction worm, usually arranged in a tubular body, and in which they form a movable plug. This is generally done so as to carefully balance the quantities of excavated material and evacuated material in order to maintain a predetermined overpressure in the containment chamber.

Such a shield, called earth pressure shield, is for example described in French patent application n ° 2.585.067. When earth pressure shields are used, the cuttings are usually mixed with heavy sludge, in particular for facilitate their evacuation. However, this heavy sludge leads to numerous drawbacks, in particular the need to set up a large-capacity sludge production plant and the subsequent treatment of cuttings made muddy. The Japanese patent application filed under n ° 119116/1978 discloses a method of excavating tunnels by means of a ground pressure shield according to which foam injected at the front of the cutting disc is injected by activation of a solution of a tension- active or protein.

These foams not only make it possible to obviate the drawbacks of heavy sludge, but in addition they are reputed to be able to reduce the friction of the cutting disc on the cutting face, and to give the cuttings a fluidity improving their evacuation as well as their impermeability to water. 'water.

This last characteristic is particularly important during excavation in soft ground, in particular sandy or sandy-gravel soils, with a high level of the water table, inducing phenomena of water gushing through the mobile plug of cuttings located at worm screw level. It is therefore important to give the mobile plug of cuttings removed by such a worm, the greatest possible impermeability.

However, it has been observed that in loose soils rich in water, in particular sandy or sandy-gravelly soils, a foam generated by a surfactant or a protein does not make it possible to impart sufficient impermeability to water, so that spurts of water still occur.

Furthermore, it has been found that this type of foam is not suitable for the excavation of very compact clay soils since it does not always allow sufficient lubrication of the cuttings, thus risking blocking the worm .

In addition, these foams are generally not very stable over time and therefore have a relatively short half-life time.

Therefore, the time to convey them from the point where they are formed to the digging shield and then at the exit of the worm, these foams are destabilized and can no longer play their role as lubricant and waterproofing agent for the plug. mobile.

A first object of the invention consists of a method making it possible to improve the waterproofing of the movable plug of the cuttings situated at the level of the worm, especially during the excavation of loose ground of the sandy or sandy type. -gravelly.

A second object of the invention consists in improving the fluidity of cuttings, in particular during the excavation of compact clay soils. 93/22538 PCI7FR93 / 00394

Another object of the invention then consists in allowing the excavation of tunnels through various geological formations arranged continuously, by means of the same shield, in particular an earth pressure shield.

Another object of the invention consists in reducing the sticking and clogging of the cuttings, in particular in the opening slots of the cutting disc, in the containment chamber of the shield, and at the level of the extraction worm.

Yet another object of the invention is to make it possible to reduce the energy necessary for the removal of cuttings, in particular at the level of the worm.

The present invention thus consists of a method of excavating tunnels by means of a digging shield, in particular a shield of the earth pressure type, comprising a cutting disc and a confinement chamber, characterized in that one injects a foam at the front of said cutting disc and / or in said confinement chamber, said foam being generated by activation of a foaming agent comprising at least one surfactant and at least one foaming aid chosen from the group consisting of fatty amines, fatty alcohols in C.-C _3Q , fatty alkylolamides and ternary amino-oxides.

Some of the above foaming agents are already known as such, but for applications in which the foams they generate are subjected to conditions very different from those encountered during the excavation of tunnels. Thus these foaming agents are usually used to form foams for extinguishing fires or as a protective agent against freezing of plants, or are used in the composition of shampoos or household detergents.

The preferred foaming aids in the context of the present invention are the fatty amines of formula:

/ ^R l

H - N

where R, is a hydrogen atom or a hydrocarbon radical, linear or branched, saturated or unsaturated, in C, - C and R ₂ is a hydrocarbon radical, linear or branched, saturated or unsaturated in C. - C, _Q. More particul f cally, R, and R ", identical or different, represent an alkyl radical in C - C, _g.

Advantageously, such fatty amines can be chosen from stearylamines, laurylamines, ketylamines, myristylamines, decylamines, octylamines, 2-ethylhexylamines, or mixtures thereof, such as those which result from the fatty acids derived from the oils of copra or palm, total or after fractionation. Laurylamine and the amines obtained from coconut fatty acids are very particularly preferred.

Fatty alkylolamides which can constitute foaming aids are typically obtained by condensation of a fatty acid in C. - C _3Q with an alkylol, such as monoéthonalamine, diethanolamine or Tisopropanolamine.

The preferred tertiary amino oxides are those of formula:

where RR and R

3 '4 5 are identical or different and represent a hydrocarbon radical, linear or branched, saturated or unsaturated, in

C, - C _3Q , at least one of R ₃ , R. or R ₅ representing a hydrocarbon radical, linear or branched, saturated or unsaturated with C. - C _3Q .

The surfactant constituting said foaming agent can be chosen from alkyl sulphates such as ammonium alkyl sulphates prepared from lauric alcohol, in particular natural lauric alcohol obtained by distillation of coconut alcohols or monoisopropanolamine alkyl sulphates, betaines, such as alkylbetaines or alkylamidobetaines, in particular those comprising an alkyl radical in

C. - C, g such as alkylbetaines and alkylamidobetaines prepared from a fatty chain obtained from coconut oil, mixtures of alkylamidobetaines and sodium alkylsulfosuccinates where the alkyl radical is in C. - C, „ and in particular those resulting from coconut oil, alkyl ether sulfates, in particular those where the alkyl radical is in C. -

C, ₈ , and preferably sodium alkyl ether sulphates prepared from lauric alcohol, sulphonates, such as alpha olefins sulphonates, alkylpolyglycosides of formula:

R - (0CH ₂ CH _{2) n} - (6), where R is a hydrocarbon radical, linear or branched, saturated ^' or unsaturated with Cg - C ₂ -

G is a C ₅ - Cg reducing sugar such as galactose, glucose or fructose, n is a number between 0 and 20, and m is a number between 1 and 10.

In the context of the present invention, the alkyloglycosides are preferred surfactants.

The proportion of foaming aids can be from 1 to 50%, preferably from 2 to 15% relative to the weight of the surfactants.

When activated in order to generate a foam according to the invention, the foaming agents are usually in solution, generally in aqueous solution, in concentrations which may be between 0.1 and 4%, preferably between 0.3 and 1 , 5% by weight.

In addition to a surfactant and a foaming aid, the foaming agent can also comprise one or more polymers or copolymers, natural or synthetic, such as polyalkylene glycols, polysaccharides, proteins, polymers and copolymers comprising acrylic, metacrylic units, acrylamides, carboxylic and / or vinyl, such as polyvinyl alcohols.

The proportion of these polymers can be between 0.1 and 6% by weight relative to the foaming agent.

The foam can be generated conventionally by activation of a foaming agent as defined above, usually dissolved, said activation being able to be carried out by the introduction of a gas, preferably a compressed gas, such as air or nitrogen, in the foaming agent in solution.

Preferably, the foaming agent in solution is activated so that the expansion coefficient K, measured at atmospheric pressure, is greater than or equal to 20, preferably between 30 and 40, the expansion coefficient K being determined by the following relation:

V m

K

V a where Vm is the volume of the foam after activation of the foaming agent in solution and Va is the volume of the foaming agent in solution before activation. The activation of the foaming agent can be carried out conventionally in a foam generator. The foam thus obtained can then be injected by suitable means, at the front of the cutting disc and / or into the confinement chamber where it mixes with the cuttings. This foam makes it possible in particular to significantly reduce the friction of the cutting disc on the cutting face and to give the mobile plug of cuttings located at the level of the worm an excellent impermeability to water. Furthermore, this foam is very stable although it is subjected to pressures greater than atmospheric pressure and shear stresses prevailing on the front face of the cutting cylinder, in the confinement chamber and at the level of the worm . The pressure pressures are generally

5 5 greater than 1.5.10 Pa, and more generally between 2.10 and

5

4. 10 Pa. In addition, the cuttings mixed with the foam can be removed from the digging shield without having to be subsequently treated, the foam absorbing itself.

According to another aspect, the invention also relates to the use of a foaming agent in solution, as defined above, for the excavation of a tunnel in particular by means of a digging shield, such as a earth pressure.

The invention also relates to a new composition which can be used as a foaming agent, comprising at least one alkylpolyglycoside and as a foaming aid, at least one fatty amine as defined above.

The preferred alkyl polyglycosides are those of formula:

R - (0CH ₂ CH ₂ ) _n - (G) _m where R is an alkyl radical, linear or branched in C „- C,., G is glucose or fructose, n is 0 and m is between 1 and 5 more particularly between 1 and 2.

Such a composition makes it possible to obtain a foam which has very great stability without affecting its expansion.

(or foam height). However, if stability over time is an important parameter that a foam must have, its expansion can also consist of a parameter to be taken into account to assess its quality. Indeed, a good expansion translates the amount of energy, the time and therefore the ease of generating the foam. Thus, the higher the expansion, the less energy and time it takes to generate a given volume of foam. In addition, the foams obtained from this composition are non-toxic and biodegradable.

In addition to its use for excavating tunnels according to the method of the invention, the new foaming agent can be used in conventional applications of this type of composition.

In particular, it can be used in cleaning or cosmetic detergent compositions, such as shampoos, or to generate foams with a view to extinguishing fires or protecting plants from frost.

The following examples are intended to illustrate the present invention.

Example 1

In order to assess the permeability to water of a cuttings, the filtration speed of the water is measured through a layer of standard thickness of this cuttings, mixed or not with a foam, under standard pressure. .

The cuttings tested are standard sand. To obtain a sand-foam mixture, 30% by volume of foam is mixed with 70% by volume of sand.

The foam is generated by activation with air of an aqueous solution at 1% by weight of a foaming agent A and a foaming agent B, according to the invention, and, for comparison, of an agent foaming agent C, not representative of the invention. The activation is such that the expansion coefficient K is equal to 10.

The foaming agent A comprises, as foaming auxiliary, a primary fatty amine whose hydrophobic chain corresponds to that of the total acids of the coconut and a surfactant consisting of sodium lauryl ether sulphate. The concentration of fatty amine is 2% by weight relative to the surfactant.

The foaming agent B comprises 15% of the same foaming aid, relative to the weight of the surfactant consisting of cocoamidopropylbetaine.

The foaming agent C only contains the surfactant of the foaming agent A, ie a sodium lauryl ether sulfate. The results obtained are shown in Table I above.

Table I

The mixing of the cuttings with a foam generated by activation of a foaming agent according to the invention therefore considerably increases the impermeability to water of these cuttings.

Example 2

Using foaming agents A and B, of Example 1, and dissolved in water at a concentration of 1% by weight, a foam A and a foam B are generated with an expansion coefficient K = 30 (at atmospheric pressure).

The foams are cut in a pressure enclosure of 3.10 Pa.

The stability of the foams under this pressure is expressed in time necessary for half of the volume of the initial solution which served to generate the foam, to be wrung out of this foam.

The half-life time thus measured is 2H10 for foam A, it is 1h25 for foam B. / 22538 P 93 0394

Example 3

Foaming agents D to H are prepared according to the invention, by mixing a surfactant, a primary fatty amine, the hydrophobic chain of which corresponds to that of the total acids of copra and city water.

By way of comparison, foaming agents D 'to H' are prepared by mixing a surfactant and tap water.

The compositions of these foaming agents, expressed in% by weight of active material, are shown in Table II below.

TABLE II

'' C 1, _n 0 alkylpolyglucoside marketed by the company SEPPIC,

(2) Alpha olefin sulfonate sold by the company AKZO. (3) A idobetaine marketed by the company SEPPIC. (4) Amidobetaine marketed by the company SEPPIC. These foaming agents are then miss in solution at 1% by weight in OMS hard water.

These solutions are introduced into graduated cylinders of 250 ml, then subjected to stirring for 2 minutes at 3,000 rpm using a Microvortex, to generate foams.

The half-life time (in s.) At atmospheric pressure and the expansion (foam height in mm) of these foams are measured. The results obtained are shown in Table III below.

TABLE III

In view of these results, it can be seen that the foaming agents according to the invention make it possible to significantly improve the half-life time and therefore the stability of the foams which they generate. It may also be noted that the expansion obtained with the foaming agent D according to the invention is, surprisingly, greater than that obtained with the foaming agent D ', comparative.

Claims

38 CLAIMS

1. Method for excavating tunnels using a digging shield, in particular an earth pressure type shield, comprising a cutting disc and a confinement chamber characterized in that a foam is injected at the front of said cutting disc and/or in said confinement chamber, said foam being generated by activation of a foaming agent comprising at least one surfactant and at least one foaming auxiliary chosen from the group consisting of fatty amines, alcohols C.-C ₃₀ fatty acids, fatty alkylolamides and ternary amino oxides.

2. Method according to claim 1 characterized in that the foaming auxiliary is a fatty amine of formula:

H - N A

where R, is a hydrogen atom or a hydrocarbon radical, linear or branched, saturated or unsaturated in C, - C _3Q and R ₂ is a hydrocarbon radical, linear or branched, saturated or unsaturated in C. - C _3Q .

3. Method according to claim 2 characterized in that R, and R ₂ identical or different? represent a C. - C.g. alkyl radical.

4. Method according to one of claims 2 and 3 characterized in that the fatty amine is chosen from stearylamines, cetylamines, myristylamines, laurylamines, decylamines, octylamines, 2-ethylhexylamines, or their mixtures, such as those which result from the amination of fatty acids from copra or palm oils, total or after fractionation.

5. Method according to one of claims 2 to 4 characterized in that the fatty amine is laurylamine or amines obtained from copra fatty acids.

6. Method according to one of the preceding claims, characterized in that the ^surfactant is chosen from alkyl sulfates such as ammonium alkyl sulfates prepared from lauric alcohol, or monoisopropanolamine alkyl sulfates, betaines, such as alkyl betaines or alkylamidobetaines, in particular those containing a C. - C,g alkyl radical such as alkylbetaines and alkylamidobetaines prepared from a fatty chain derived from coconut oil, mixtures of alkylamidobetaines and sodium alkylsulfosuccinates, where the alkyl radical is in C. - C, g and in particular those derived from coconut oil, alkyl ether sulfates, in particular those where the alkyl radical is in C- - C, _g , and preferably sodium alkyl ether sulfates prepared from lauric alcohol, - sulfonates, such as alpha olefin sulfonates, alkyl polyglycosides of formula

R - (0CH ₂ CH _2)n - (6). where R is a hydrocarbon radical, linear or branched, saturated or unsaturated in C„-C„.,

G is a C _ς - Cg reducing sugar such as galactose, glucose or fructose, n is a number between 0 and 20, and m is a number between 1 and 10.

7. Method according to one of the preceding claims, characterized in that the proportion of foaming auxiliary is 1 to 50%, preferably 2 to 15% relative to the weight of the surfactants.

8. Method according to one of the preceding claims characterized in that the foaming agent is in solution, preferably in aqueous solution.

9. Method according to claim 8 characterized in that the concentration of the foaming agent in the solution is between 0.1 and 4%, preferably between 0.3 and 1.5% by weight.

10. Method according to one of the preceding claims characterized in that the foaming agent further comprises one or more natural or synthetic polymers, such as polyalkylene glycols, polysaccharides, proteins, polymers or copolymers comprising acrylic, methacrylic, acrylamides, carboxylic and/or vinyl, such as polyvinyl alcohols.

11. Method according to one of the preceding claims characterized in that the injected foam is subjected to a pressure greater than

5 5

1.5.10 Pa, preferably at a pressure between 2.10 and

4.10 ⁵ Pa.

12. Method according to one of the preceding claims characterized in that the expansion coefficient K of the foam, at atmospheric pressure, is greater than or equal to 20, preferably between 30 and 40.

13. Method according to one of the preceding claims, characterized in that the foaming agent is activated by introducing a gas such as air or nitrogen.

14. Use of a foaming agent comprising at least one surfactant and at least one foaming auxiliary as defined in one of claims 1 to 7 for the excavation of a tunnel.

15. Foaming agent comprising an alkylpolyglycoside of formula:

R - (0CH ₂ CH ₂ ) _n - (G) _m or R is a hydrocarbon radical, linear or branched, saturated or unsaturated, in C _Q - C« ₄ . G is a C ₅ - C reducing sugar _g , n is a number between 0 and 20, m is a number between 1 and 10. and a fatty amine as defined in one of claims 1 to 5.

16. Foaming agent according to claim 15 characterized in that R is an alkyl radical, linear or branched in C _β - C,., G is glucose or fructose, n is equal to 0 and m is between 1 and 5 , preferably between 1 and 2.